In the combine above, upon a speed change operation being performed with a continuously variable transmission unit, the rotation speed of drive force that is output from the continuously variable transmission unit changes, the rotation speed of a combined drive force that is output by a planetary power transmission unit combining the drive force from the continuously variable transmission unit and drive force from an engine changes, and the combined drive force having the rotation speed thus changed is transmitted to a travelling apparatus. Thus, it is possible to drive the travelling apparatus while smoothly changing the speed of the travelling apparatus by performing a simple speed change operation with a continuously variable transmission unit. Also, since the drive force from the continuously variable transmission unit and the drive force from the engine are combined by the planetary power transmission unit and the combined drive force is transmitted to the travelling apparatus, it is possible to efficiently transmit the engine's output to the travelling apparatus.
Conventional examples of this kind of combine include the combine disclosed in Patent Document 1. This combine includes an input shaft that receives an input of drive force from the engine, and a hydraulic continuously variable transmission that serves as a hydraulic continuously variable transmission unit is configured with a hydraulic continuously variable transmission unit that has: a hydraulic pump that receives an input of the drive force of the input shaft; and a hydraulic motor that is driven by the hydraulic pump, and a configuration is adopted in which the drive force of the input shaft and the output from the hydraulic continuously variable transmission apparatus are input to the planetary power transmission unit and combined, and the combined drive force, which is output from the planetary power transmission unit, is transmitted to the travelling apparatus.